Trends in Ischemic Heart Disease Death Rates for Blacks and Whites -- United States, 1981-1995

During 1995, ischemic heart disease (IHD) caused 21% of all
deaths and 65% of deaths attributed to heart disease (1). Few
reports comparing IHD mortality between blacks and whites have
presented age-specific rates (2,3), and none have compared trends
over time. This report examines the trend in age-specific IHD death
rates for blacks and whites from 1981 through 1995 (the latest year
for which data are available) and indicates that, in the younger
age groups (35-64 years), blacks have a higher risk for IHD death
than whites.

Average annual age-adjusted and age-specific IHD death rates
for persons aged greater than or equal to 35 years during
1981-1985,
1986-1990, and 1991-1995 were calculated from mortality data
compiled by CDC and population data compiled by the Bureau of the
Census. For each of the rate calculations, the numerator was the
average annual number of deaths during the period and the
denominator was the average of the five mid-year population
estimates during the period. IHD deaths were defined as deaths for
which the underlying cause was listed as codes 410.0-414.9 of the
International Classification of Diseases, Ninth Revision (ICD-9).
The cause of death is reported by attending physicians, medical
examiners, or coroners on death certificates filed in state vital
statistics offices. Age-adjusted IHD death rates for persons aged
greater than or equal to 35 years were calculated by the direct
method using the 1970 U.S. standard population. Age-specific death
rates were calculated for 10-year age groups. Black:white mortality
ratios were calculated by dividing the death rate for blacks by the
death rate for whites. Black:white mortality ratios for each year
during 1981-1995 also were examined and indicated the same trends
as the average annual mortality ratios for the 5-year periods
presented here.

From 1981 through 1995, age-adjusted IHD death rates decreased
for blacks and whites of both sexes (Table_1). The age-adjusted
IHD
mortality ratios for blacks compared with whites increased from 0.9
to 1.1 overall. For each time period, the age-adjusted black:white
IHD mortality ratios were less than 1.0 for men and greater than
1.0 for women.

The age-specific IHD death rates increased with increasing age
for blacks and whites of both sexes (Table_1). The age-specific
IHD
mortality ratios were greater than 1.0 in younger age groups, where
death rates for blacks exceeded those for whites, and were less
than 1.0 in older age groups, where death rates for whites exceeded
those for blacks. This crossover of mortality ratios occurred in
different age groups for men and women. For example, during
1981-1985,
the mortality ratios for men were less than 1.0 in the 65-74-year
age
group and those for women were less than 1.0 in the 75-84-year age
group. In every age group, IHD death rates were greater
for men than women, and age-specific black:white mortality ratios
were greater for women than men.

From 1981 through 1995, age-specific IHD death rates decreased
for blacks and whites within each sex and age group except for
black women aged greater than or equal to 85 years (Table_1).
However, these decreases were greater for whites than blacks during
this period, resulting in a greater disparity of IHD death rates
between blacks and whites and in increasing black:white mortality
ratios. The age-specific black:white mortality ratios increased in
every age group overall, and the black:white mortality ratios
increased across the three 5-year periods for men (Figure_1)
and
women (Figure_2) of every age group except the 35-44-year age
group. This increase in the mortality ratios resulted in a shifting
of the age groups at which death rates for blacks exceeded those
for whites, such that the disparity between young blacks and whites
extended into older age groups. For example, during 1981-1985, the
total age-specific black:white mortality ratios remained greater
than 1.0 until the 65-74-year age group, but during 1991-1995 these
mortality ratios remained greater than 1.0 until the 75-84-year age
group.

Editorial Note

Editorial Note: The findings in this report indicate that IHD death
rates declined for all age groups during 1981-1995; however, these
decreases were greater for whites than for blacks, causing an
increase in the black:white IHD mortality ratios. Black: white
mortality ratios were particularly high for young women; black
women in the 35-44- and 45-54-year age groups experienced IHD death
rates more than twice those of white women in the same age groups.
Furthermore, the disparity in IHD death rates between blacks and
whites in the younger age groups increased and extended into older
age groups during this period. By 1991-1995, the black:white
mortality ratios were less than 1.0 only in the 75-84- and greater
than or equal to 85-year age groups for men and in the greater than
or equal to 85-year age group for women. In addition, among the
older age groups, where death rates for whites exceeded those for
blacks, the gap appeared to be closing over time, with the
black:white mortality ratios increasing toward 1.0.

Since the mid-1970s, whites (especially white men) have
experienced greater declines than blacks in age-adjusted IHD death
rates (4-6). Although this report found that blacks had either
similar or lower age-adjusted rates during 1981-1995, the
age-specific rates for this period showed a notable race disparity
for persons aged 35-64 years. Death rates for these younger age
groups were considerably lower than those for older age groups.
Nonetheless, the increased risk for IHD death among younger black
men and women represents a substantial number of years of potential
life lost.

IHD death rates are affected by changes in modifiable risk
factors associated with IHD and the successful diagnostic and
treatment efforts in preventing mortality. The disparities in early
IHD death rates by race in this report probably reflect differing
distributions of risk factors (e.g., cigarette smoking, body
weight, diabetes, and hypertension) and socioeconomic status (2).
Other potential explanations for the increasing disparity between
blacks and whites in premature IHD mortality include increasing
differentials over time in the detection and treatment of IHD risk
factors and in the quality of acute, in-hospital, and/or
post-hospital medical care for IHD. In addition, the variation in
physician, coroner, and medical examiner practices in reporting IHD
on death certificates may have contributed to these differences.
Compared with whites, blacks have a higher prevalence of some IHD
risk factors (e.g., hypertension and diabetes) (6), are less likely
to receive certain diagnostic and therapeutic coronary procedures
(7,8), and may have a higher proportion of sudden and
out-of-hospital deaths from IHD (9).

Public health research and intervention efforts are needed to
determine and address the underlying factors associated with the
greater risk for IHD death among younger (aged less than 65 years)
blacks than among younger whites and to address the slower decline
in the IHD death rates among blacks of all ages. The continued
monitoring of age-specific IHD mortality by race/ethnicity,
continued monitoring of the prevalence of modifiable risk factors
for IHD by race/ethnicity, and collection and analysis of
population-based data on IHD incidence and treatment should be
conducted to monitor the success of public health efforts to reduce
IHD morbidity and mortality. Setting objectives for reductions in
IHD mortality among persons aged less than 65 years also may be
useful. CDC recently awarded funds to eight states to develop
programs for the prevention of cardiovascular disease, including
IHD. These programs will emphasize development of policies and
environmental changes to reduce and prevent cardiovascular
diseases. In particular, these programs will target cardiovascular
diseases in minority and low-income populations.

National Heart, Lung, and Blood Institute. Morbidity and
mortality: 1996 chartbook on cardiovascular, lung, and blood
diseases. Bethesda, Maryland: US Department of Health and Human
Services, National Institutes of Health, National Heart, Lung,
and
Blood Institute, 1996.

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